Transmission of intelligence by electric means.



PATBNTBD AUG.- 2o, 1907,.

I. KITSEE. 0F INTELLIGENCE BY LBGTRIC MEANS. APPLIoATIoN FILED Fna. 5. 1904.

' TRANSMISSION ITNESSFS n E fh 0L no: E QQ DNNIQQ INI nur nouns Ermes to.. vAsnlNamN n c ISIDOR KITSEE, OF PHILADELPHIA, PEbl-NSTYLVANIA.

TRANSMISSION os INTELLIGENCEMBY ELECTRIC MEANS.

Specification of Letters Patent;

Patented Aug. 20, 1907.

Application le'd February 5,1904. Serial No. 102,229.

To all 'whom it may concern:

Be it known that I, IsIDon Krrsnn, of the city and county of Philadelphia, State of Pennsylvania, have invented certain new and useful Improvements in the Transmission of Intelligence by Electric Means, of which the following is a specification.

My invention relates to an improvement in the transmission of intelligence by electric means and has more special reference to transmission wherein mechanical energy is converted at the sending station into electric energy and re-converted again into mechanical energy at the receiving station. such for instance as the transmission of speech with the aid of a telephonie sender and receiver.

In telephony, an all-metallic circuit is now almost universally employed in preference to the earth-return, for the reason that through the grounding of the line, the earth currents interfere too seriously with the transmission of speech. I have discovered that it is possible, under certain circumstances, to communicate telephonically between two stations more or less remote from each other with only one metallic line and without using the earth as a return, The underlying principle of this my invention lies in the employment of a local artificial line, preferably all-metallic, preferably joined together by condensers, which are preferably shunted with the aid of magnetic coils.

It is unnecessary for me to repeat here all the experiments made to obtain the most efficient arrangement and it snflicesto repeat onlyone of these experiments, in which I employed two stations, located in different rooms removed from each other by a hallway, and in which the line itself consisted to its greater part of iron wire. At each of the stations the artificial local circuit consisted, besides the transmitting and receiving instruments, of resistances with the combined value of about 15,000 ohms, of an inductance of about 100 Henrys and of capacity devices with a combined value of about 8 micro-farads. The line itself joining these two stations to each other consisted of about 5 miles of iron wire No. 28, and also of two coils` each of about 5000 ohms resistance and an iuductance of about 44 Henrys, and of condenscrs with a capacity of about 6 micro-farads. The local circuits as well as the line joining the same was carefully insulated from the ground and large porcelain insulators were used in every case and the test showed that no leakage to the ground whatsoever from the local circuit or line existed. The transmitting force at each station consisted of three dry cells and the speech could be heard distinctly at both terminals.

To prove the theory that it is necessary to build up the local line to a value equal or higher than the line joining the two stations, the indnctance was removed from one of the local circuits with the result that the speech could not be heard at all: as this inductance consisted of a series of individual coils, one of these coils was re-inserted in the line with the result that the voice could be heard but the Words could not easily be distinguished. The gradual insertion of all of the series of coils resulted in the gradual increase in the clearness 0,1' the transmitted speech, till with the insertion of the last of the series of coils, the former distinctness was again obtained. The removal and re-insertion of the condensers efect'the speech transziiitted in the same manner, so also the relnoval and rc-insertion of the ohmic resistance. After a full balance was obtained. the ohmic resistance and inductance of the line joining these two stations was.A increased about of its former value andi the clearness of the speech rapidly decreased With the insertion of these new devices.

In the drawings. Figure 1 is a diagrammatic view illustrating one form of the herein-described invention. Fig. 2 is a similar view illustrating the local and line connections to the condensers.

Referring now to the drawing, and in which similar letters indicate similar parts,-1 and 1L are the two stations joined together by the line 2. At cach of these stations A represents-a battery, l5 a telcphonic transmitter, C a magneto, c the bell for samc, and G thc ground for said bell. As usual, the magncto contacts through the lever with the lino as long as the rcccivcr is in its place, but breaks this contact as soon as thc receiver is removed. In the drawing, this arrangement. is shown by lever b and contact yl. 'l`hc battery A connects with said lever as soon as through thc rcmoral of the receiver the lever contacts with thc point IF. In this circuit is incloscd the primary of thc device I); this primary is connected with one polc to thc secondary d; this secondary is connected to thc artificial linc. As this device does not form a special part of this my invention, it is unnecessary to go more into dctail of same. or to point out the reasons of the pcculiar construction of same. The artificial line itself consists of thc rcs-istanccs h, capacity devices, shown in thc drawing as condensers i, inductanccs, shown hcrc as chtetro-magnetic coils j, and coreless coils k, which may perform the function of inductance as well as rctarding coils. The terminals of cach of these lines are conncctcd to condenscrs and these condensers are shunted with thc aid 0f low resistance coils having a grcat magnetic. flux through their soft iron cores. Thcso coils are indicated by the letters N and N1 and the condcnscrs by the letters M and M1, rcspectivcly. 'lhc condenscrs M and M1 are double condense-rs, and form thc subject of a separate application filed .Tune 2G, 1897, Ser. No. 642,495. The receiving device consists of the device F in conjunction with the reccivcr E. The device F embraces the coil f1 in which is inserted the coil f joined with one terminal to one terminal of the first named coil. In reality, this arrangement may bc likened to an inductorium and as the special features of same do not form part of thisl my invention, I do not describe them in particular and only state that the receiver E has to be in electrical connection with the coil f which, if the similarity of the inductorium is carried out, may represent the primary of same.

To conveniently adjust the local circuits so as to conform with the line-proper, I have provided each of the devices with the plug m in electrical contact with that part of the line to which its particular device pertains. With the aid of this device, it is an easy matter to plugin or out one or more of'the resistances, capacities or inductances, as it is self-evident that the line supposedly running from Philadelphia to Chicago requires a balancing local ot' greater value than a line running from Philadelphia to New York. The parts of the local circuit as well as the line-proper should be well insulated and the grounding of any part, with the exception of the grounding o the bell and magneto when no speech is transmitted, should positively be avoided.

The modus operand@` as far as the operation is concerned, is the same as in the usual individual long distance telephony: The person calling rings-up the second station, awaits an answer, and then removes the receiver from the hook. The second station, answering, has also to remove his receiver. This removing of both receivers breaks entirely the connection of the line with the ground and if, as said above, all parts are well insulated, a one-line circuit without a ground is established.

These, in broad outlines, are the main features of my invention and I have illustrated here an individual line scasa give a clear conception oi the whole arrangement, but it is obvious that this arrangement may also be used in connection with a central station.

Having now described my invention, what I lclaim as new and desire to secure by Letters Patent is 1. An electric line ot' transmission. consisting of two local circuits more er less remote from each other and a line joining said local circuits, each of said local circuits having :1 value at least equal to the value of the line proper.

2. As a means to electrically communicate between two points more or less remote fron. each other, over a onclegged line without earth connection. artificial local circuits at each of said points. each of said local circuits having: a value at least equal to the value ot' the line-proper. the terminals of the line-proper connected to said loca! circuits.

Z-I. In combination with a line ot electric transmission. t\vo local circuils possessing ohmc resistance, capacity and inductance. of means to vary said values. said local circuits connected to said line of transmission through condensing.r devices.

4. Means to communicate electrically between two points mol'e or less remote from each other, said means embracing telephonie transmitters including.: in their circuits sources of energy. a local'circuit at each point embracing devices to Jive said circuits an ohmic value. a cnpacity and inductance. telephonie receivers and a conductor connecting both of 'said local circuits to each other.

In testimony whereof. I hereby sign my name in the presence o1' two subscribing witnesses. this third day ot" l `ebruary. A. l). 11m-i.

ISIDOR Kl'lSEE.

Witnesses li. M. Pori-ran. lnrrrr R. STILLur.

because to persons versed in the art this will readily' 

